IMHO.....find some HXP M2 (or US Military Surplus M2 if you can find it). Be careful about paying too much for corrosive primed ammo (some years of US M2 is corrosive). Then, as far as I know.....HXP is not corrosive primed.
If all else fails.....
Then......
I'd try the new commercial stuff. .30-06, 150 grain, PPU is normally recommended. But truthfully, I haven't used it (also true for S&B ammo).
Yup......I got plenty of HXP.
As for the.....
Korean ammo......OK, the KA surplus stuff I'd stay away from. PS surplus.....I'd try it, though some lot #s of PS is questionable. So, don't stock up. Unless you've tried it. And, again......be careful about corrosive primed lots. Then, the recent mfn PMC was said to be OK.
Here is my HXP surplus. Shot through my service grade Greek repatriated H&R M1.
Aloha, Mark